Arcing horn and hinge mechanisms for disconnect switches



April 26, 1966 G. R. M CLOUD ARCING HORN AND HINGE MECHANISMS FORDISCONNECT SWITCHES 2 Sheets-Sheet 1 Filed Oct. 28, 1963 p Y, mm W Na eE m W 7 IPA. a 4

April 1966 G. R. M CLOUD 3,248,510

ARCING HORN AND HINGE MECHANISMS FOR DISCONNEGT SWITCHES Filed 001;. 28,1963 2 Sheets-Sheet 2 41-rae/VEY United States Patent 3,248,510 ARCINGHORN AND HINGE MECHANISMS FOR DISCONNECT SWITCHES George R. McCloud,South Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee,Wis., a corporation of Delaware Filed Oct. 28, 1963, Ser. No. 319,432 3Claims. (Cl. 200162) The present invention relates to switches and moreparticularly to improved arcing horn latching and hinge structures for ahigh voltage disconnect switch.

In the disconnect switch of the present invention the applicant hasprovided a device that combines the use of the most economicalcommercially used highly conductive material, strip copper in anenvironment utilizing a minimum number of current interchanges. This isaccomplished by using strip copper terminal members with a single stripof this material forming both the terminal pad and the blade contactingportion at both the pivot end and latch end of the blade assembly ratherthan using either built up terminal members having multiple currentinterchanges or using a one piece cast element composed of a materialsuch as brass wherein the zinc content impairs the electricalconductivity. The use of round edge strip material for these switchelements also provides relatively high pressure single line electricalcontact with the engaging blades without the necessity of additionalmachining or forming operations. In addition the arcing horn is disposed'betwen the blades and is latched by engagement with a curved surfaceformed in the copper strip that serves as the contact at the latch endto provide not onl the latching function, but also for withdrawal of thearcing horn from the latch without engaging the terminal contactsurface. The simple mechanical design of this switch minimizes theeffects of heating and corrosion for the life of the switch and alsoprovides an inherent capability to withstand momentary short circuitcurrents. With the blades disposed at either side of the contactingterminal members, the magnetic field caused by a fault current causesthe blades to be drawn together and therefore during such a conditionwhen a substantial magnetic field is established the contact pressure,and consequently the conductivity at the location of currentinterchange, is increased.

At the hinge end the hinge portion of the terminal is formed by pierceextruding the strip to avoid the necessity of a 90-degree bend and theadditional current interchange required by the conventional hingefabrication. A similarly forme-d strip used for the latch end terminalmember also functions as a blade guide.

Also provided by the switch of the present invention is an arcing horn,quick break mechanism which is disposed between the switch blades toprevent accidental bending or damage. The latch associated with thearcing horn is incorporated into the copper strip stationary con tactand guide member and obviates any additional parts being required inassociated with the terminal assembly.

It is an object of this invention to provide a disconnect switch havinga minimum number of current exchanges while being made of the mosthighly conductive commercial materials.

It is a further object of this invention to provide a quick breakmechanism or arcing horn utilizing the principal stationary contactmember to provide the guiding and latching function.

It is also an object of this invention to provide a disconnect switch,that is economical to manufacture, of simple durable construction andreliable in use.

These and other objects and advantages of this invention will becomeapparent from the following description 3,243,519 Patented Apr. 26, 1966when taken in connection with the accompanying drawings wherein:

FIG. 1 is a plan view of the disconnect switch embodying the presentinvention;

FIG.v 2 is a side elevation of the disconnect switch of FIG. 1 with theinsulators and base partially broken away;

FIG. 3 is a partial vertical transverse section taken along line 33 ofFIG. 2;

FIG. 4 is a side elevation of the switch blade and stationary contactterminal assemblies, partially in section and partially broken away,with a phantom view showing the switch blades partially disengaged; and

FIG. 5 is a partial side elevation of the switch of FIG. 1, showing theswitch blades in a disconnected condition with the arcing horn stillmaintaining contact with the sta- The terminal assembly is secured at anintermediate location to the insulator 15 by bolts 19 that arethreadably received by the bracket 21 carried by the insulator. At

one end the strip extends longitudinally and forms a terminal pad 23which cooperates with the terminal 24 mounted thereon by bolts 25 andthe opposite end 26 extends upwardly and is pierced extruded to receiveand retain the cylindrical shank of a'bolt 27 in closely contactingrelation therewith. A reinforcing bar 29 extends from a rivetedconnection with the upwardly extending strip end 26 to a sloted opening31 in the strip where it is re tained in fixed'relation by having theshoulder surfaces 33 abut one side and the turned tab 35 engage theopposite side.

The latch end terminal assembly 37 has a single strip of round edgecopper material formed to provide both a terminal pad 38 and astationary contact 39. The strip copper material referred to as roundedge is strip material commonly formed by rolling round rods into stripmaterial which yields a strip having a curved edge of nominally roundconfiguration which is free of sharp edges. The assembly 37 is securedto bracket 40 carried by the insulator 14 by the bolts 41 and a terminal43 cooperates with the terminal pad 38 on which it is mounted by bolts44. The stationary contact 39 (also shown in FIG. 3) provides paralleltransverse edge surfaces 46 with a terminal portion 47 wherein thetransverse edge surfaces converge to form a blade guide. Alsoincorporated in the stationary contact 39 along one transverse edge is adepression or groove 49 formed by a curved reentrance surface that actsas a latching surface for the arcing horn 50 of the quick breakmechanism which will be described hereafter. The stationary contact 39also carries a keeper 52 that is riveted thereto. A pair of hard drawncopper switch blades 55, 56 are maintained in horizontal spaced relationintermediate the ends thereof by a sleeve '58 which extends between theblades abutting the confronting blade surfaces and a pin 59 extendingthrough the sleeve and the blades to firmly secure the switch bladesagainst the axial ends of the sleeve.

At the latch end a pin 61 extends through openings in the blades 55, 56and a spacing sleeve 62. The spacing sleeve 62 is slightly shorter inits axial direction than the distance between transverse edges 46 of thestationary contact 39 and the pin is of sufficient length to provide aspace between the head 63 of the pin 61 and the adjoining surface ofblade 55. A compression spring 60 disposed about the pin 61 applies abiasing force between the head of the pin and the switch blade to urgethe blades toward one another into contact with the axial ends of sleeve62 when the switch is pivoted to a disconnected position and intointimate wiping contact with the transverse edges 46 of stationarycontact 39 when the switch is in a closed condition with the stationarycontact disposed between the blades 55, 56. At the hinge end of theswitch the bolt 27 extends through the switch blades 55, 56 and isretained as previously stated by passing through the pierce extrudedopenings in the upwardly extending end 26 of the terminal assembly stripportion 17. The nut 65 and jamb nut 66 hold the blades 55, 56 againstthe transverse edges of the strip 18 with spring washers 67 affording abiasing means to maintain compressive wiping contact between the blades55, 56 and the round edge surfaces of the copper strip end portion 26 ofthe hinge end terminal assembly.

As seen also in FIG. 4, a latch lever 69 is mounted between the switchblades 55, 56 and secured thereto by trunnions 71 formed integrallytherewith which are received in co-axial blade openings. The latch lever69 has a depending hook 70 that cooperates with the lower latchingsurface 72 of the keeper to provide positive latching engagement whenthe switch is closed, an arm portion 73 having a curved pry out surfacethat overlies a cooperating upper pry out surface of the keeper when theswitch is closed and a nose portion 74 that extends toward and isengageable by a portion of the control lever 75. The control lever islikewise pivotally mounted on the switch blade assembly by trunnions 77(FIG. 1), formed integrally therewith, that are received in co-axialblade openings. One arm of the control lever terminates in a pull ring78 while the arm 79 engages the latch lever nose portion 74 to cause thelatch lever 69 and the control lever 75 to rotate in opposite directionsupon activation of the control lever by a pull-on ring 75. A torsionspring 81 coiled about the latch lever with one end turned about theswitch blade 56 and the other about the latch lever nose portion 74biases the latch lever 69 toward latching engagement with the keeper 52.As seen in FIG. 4, the pivotal movement of the control lever is limitedin a clockwise direction by engagement between shoulder 82 and sleeve 58and in a counterclockwise direction by engagement between the dependingportion 83 and the latch lever 69.

Mounted between the blades and carried thereby is a resilient arcinghorn 50 having a coiled portion 85 to increase its resiliency. A tab 87which is bolted to the switch blade 55 secures the arcing horn to theblade with positive positioning afforded by an end portion which extendsbeyond the tab 87 and is turned at a right angle and projects into anopening in the blade 55. The areing horn is biased toward the blade 55and the stationary contact engaging distal portion 88' is retained in aleading relation to the blade 55 as the latter is pivoted toward aclosed position by a bracket 89 riveted to the blade which has atrough-like retaining surface and a depending guide surface fordirecting the blade into the trough.

In operation, as the switch is closed, the arcing horn 50 is displacedtransversely along the shoulder of the guide bracket 89 by contact withthe guiding edge surface of the stationary contact 39. The blades 55, 56are thereafter displaced against the force of the biasing spring 60 bythe transverse guide and contact surfaces of the stationary contact 39followed by a displacement of hook member 70 of latch lever 69 againstthe biasing force of spring 81 as the hook engages the striker surfaceof the keeper 52. As the hook approaches a latched position inunderlying relation to the keeper-latching surface 72, the arcing horndistal end portion 88 enters the latching recess or groove 49 in thestationary contact followed by the 4 positive latching engagementbetween the keeper 52 and the hook 70.

Referring to FIGS. 4 and 5, when the switch is opened a force is appliedwhich is representatively shown by the arrow A overlying the pull ringof FIG. 5 which causes the control lever to pivot in a clockwisedirection and the latch lever to pivot in a counterclockwise directionfrom the full line position to the dotted line position as shown in FIG.4. The initial pivoting of the control lever causes the latch lever tobe pivoted to a position wherein the hook portion 70 no longer underliesthe latching surface 72 of the keeper and thereafter the pry-out surfaceof the latch lever arms 73 engages the pry-out surface of the keeper 52to provide a positive prying force urging the switch blades fromengagement with the stationary contact 39 to overcome any force that mayinhibit the opening of the switch such as a severe icing condition. Whenthe switch blades 55, 56 have been pivoted in a clockwise direction awayfrom engagement with stationary contact 39 as illustrated in FIG. 5, thearcing horn 50 will still remain in contact with the arcing horn latchportion 49 of the stationary contact until the switch blades have beensufficiently pivoted to draw the arcing horn wire clear of the latchingengagement with groove 49. At that time the resilience of the arcinghorn and the coiled portion will cause the arcing horn to be quicklyreturned to a normal position of contact with the recess surface of thesupport bracket 89.

Although but one embodiment has been shown and described, it will beapparent to those skilled in the art that various changes andmodifications may be made therein without departing from the spirit ofthe invention or from the scope of the appended claims.

I claim:

1. A disconnect switch comprising a blade member having a latch end anda hinge end and being pivotable between open and closed positions; anarcing horn secured to said blade member and extending adjacent saidblade member toward said latch end with the distal end thereof disposedin leading relation to said blade as said blade is pivoted toward saidclosed position; a first terminal member having said blade memberpivotally mounted thereon adjacent said hinge end; a second terminalmember including a piece of strip material presenting a blade guidingsurface and a blade contacting transverse edge surface, said guidingsurface and said contacting edge surface serving as an arcing hornguiding surface; and arcing horn latch means comprising a concavesurface extending into the strip material of said second terminal memberfrom said blade contacting edge surface, said areing horn being orientedto be withdrawn from said latch means without engaging said contactingsurface when blade member is pivoted away from said closed position.

2. A disconect switch comprising a blade assembly including a pair ofgenerally parallel switch blades interconnected for unitary pivotalmovement about a transverse axis between a first open position and asecond closed position; an arcing horn secured to said assembly; a firstterminal member hingedly connected to said blade assembly about saidtransverse axis adjacent one end of said assembly; a second terminalmember including a single piece of highly conductive round edge stripmaterial with a terminal pad portion and an upright contact portion,said upright portion extending between said blades with transverselydisposed parallel round edge portions thereof in contacting relationwith the confronting major surfaces and said blades when said assemblyis in said second position and presenting blade guide surfaces thatincline toward and merge into said blade contacting round edge surfaces;and an arcing horn retaining latch means comprising a concave surfaceextending into said second terminal strip material from one of saidparallel round edge surfaces, said latch means and arcing horn beingpositioned to prevent contact between said arcing horn and said bladeContacting surfaces when said assembly is pivoted from said secondposition to said first position and said arcing horn is withdrawn fromcontact with said second terminal member.

3. A disconnect switch comprising a blade assembly having a first closedposition and a second open position, said assembly having a pair ofsubstantially parallel blades interconnected for unitary pivotalmovement about a transverse axis; a resilient arcing horn secured tosaid assembly intermediate said blades in leading relation to saidassembly when said assembly is being pivoted toward said first position;a fixed hinge member including a single piece of highly conductive roundedge strip material having a first terminal pad portion and a secondswitch blade engaging portion extending between said blades with theround edge portions thereof abutting said blades, said blade assemblyand said hinge member second portion being longitudinally piercedintermediate said blades with strips formed thereby alternately bent toradially retain a pin extending therethrough and carried by said bladeassembly; a fixed contact member including a single piece of round edgestrip material with a third terminal pad portion and a fourth uprightcontact portion, said fourth portion extending between said blades withtransversely disposed round edge surfaces engaging the confronting majorsurfaces of said blades when said assembly is in said first position;and arcing horn latch means formed by a concave surface extendingtransversely into said fourth portion from one of said round edgesurfaces.

References Cited by the Examiner UNITED STATES PATENTS 504,528 9/ 1893Herrick 200-62 2,317,118 4/ 1943 Schultz et al. 200-62 2,803,726 8/1957Gilliland 200-48 X KATHLEEN H. CLAFFY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

WILLIAM C. GARVERT, Assistant Examiner.

1. A DISCONNECT SWITCH COMPRISING A BLADE MEMBER HAVING A LATCH END ANDA HINGE END AND BEING PIVOTABLE BETWEEN OPEN AND CLOSED POSITION; ANARCING HORN SECURED TO SAID BLADE MEMBER AND EXTENDING ADJACENT SAIDBLADE MEMBER TOWARD SAID LATCH END WITH THE DISTAL AS SAID THEREOFDISPOSED IN LEADING RELATION TO SAID BLADE AS SAID BLADE IS PIVOTEDTOWARD SAID CLOSED POSITION; A FIRST TERMINAL MEMBER HAVING SAID BLADEMEMBER PIVOTALLY MOUNTED THEREON ADJACENT SAID HINGE END; A SECONDTERMINAL MEMBER INCLUDING A PIECE OF STRIP MATERIAL PRESENTING A BLADEGUIDING SURFACE AND A BLADE CONTACTING TRANSVERSE EDGE SURFACE, SAIDGUIDING SURFACE AND SAID CONTACTING EDGE SURFACE SEVING AS AN ARCINGHORN GUIDING; SURFACE AND ARCING HORN LATCH MEANS COMPRISING A CONCAVESURFACE EXTENDING INTO THE STRIP MATERIAL OF SAID SECOND TERMINAL